In the Designer of my forms I usually have this for Singleton purposes.[code]Is there any hack in the IDE that would let me just press a button or something and it will automatically add the code I have above to the selected Designer?I can always type or copy/paste/modify it but I thought there could be something that I could set to just automate this redundant task.
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1. Generates Class files based on SQL server database.2. Generates Class properties.3.Generates Class contructors.4. Generates a Singleton class and it's corresponding Collection class.5. Outputs individual files or the code to copy and paste.
View 1 RepliesI am looking for a way to auto generate a flow chart for my VB Code, are there any tools to get this done?
View 1 RepliesFor Example: I need to develop a Small Inventory program for nearby Super Market and the need is a QR Code should be Generated for the Model Number of a Product Eg: A for Iphone and then we scan the QR Code image by Scanner connected to the PC it should automatically fill the letter " A " in the input box so that i can use that for searching the product " Iphone "
View 2 RepliesI've been trying to create a working keygen for three months and I havn't figured it out. I first inserted two buttons and named one "Generate" and the other "Exit" and then I put in a textbox. After that I put in the code and debugged it every time I pressed the Generate button a 0 just popped up in the textbox. my code is below.
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
[CODE].....................
I'm trying to make a program (in VB 2008 Express Edition) that will take text (from a textbox) and then switch the letters (say a->f and A->F) and will put the result into a second textbox when I click a button. How do I code the program so that it will search through the textbox and find all of a certain letter (say a) and replace it, then search for the next letters (say b-z) and replace them?
View 4 RepliesI need alot of help... I was making a prototype "registration code generator" that creates 25 character GUIDs and outputs them to a listbox. then after it outputs, it does this:
For Each s As Object In ListBox1.Items
For Each z As Char In s
If counter = 4 Then
counter = 0
[Code]...
Sometimes there is a need to initialize the singleton class with some helper values. But we can't "publish" a constructor for it. What is the workaround for this?overloading the GetInstance or setting a color is not my idea. The color should be set only once. I would like to be sure that MyPainter paints ONLY with the initialized color. Any default color should ever be used.
For more clarity I provide a sample:
''' <summary>
''' Singleton class MyPainter
''' </summary>
Public Class MyPainter
[code]....
I am normally a c# programmer but am now working in VB for this one project when I use to set up a singleton class I would follow the Jon Skeet model
public sealed class Singleton
{
static Singleton instance = null;
static readonly object padlock = new object();
[code]....
I get StackTracker.Instance.Instance and it keeps going, while it is not the end of the world it looks bad.is there a way in VB to hide the second instance so the user can not recursively call Instance?
I have recently discovered the singleton approach to mdi child forms and I was trying to integrate this singleton stuff into my "mChildform" class but I keep getting InvalidTypeCastException when I do so. Not sure where I am messing this up.
My mChildform class inherits Form and adds a few properties that are required by all child forms. All of my other project forms inherit this mChildform as their base type instead of form.
When I go directly to one of these forms (the logs form for example) and add
[code...]
I get the exact results that I want. Naturally, since this is something I want all child forms to be able to do I try to add it to my mChildform base class.
The code compiles, but since the reference is of mChildForm type I want to cast it to my usable form class, but it throws the InvalidCastException.
[code..]
I'm not sure why I can't cast it to the other form type, but i'm hoping someone here can explain why I cannot. The Instance() check would always fail if I do not cast my instance to another one of the types.
Since my mChildForm class only holds minimal info to do any real work I have to cast it to the other type. As a workaround I can add the instance method to each new form but I would really like to get it into the base class.
I am working on creating a customized UI composite control. This control would be a container to several other custom controls.As a first step, i am creating the container UI using a singleton pattern. This is because at any point in time only one isntance of this container is allowed to be created. This is fine.Now i want to practice interface based desgin. So i introduced a sinple interface calleD IdesignSurface which has two properties. I would like my singleton class to implement this interface,so i tried something like this and got an error saying "end of line
NotInheritable
Class DesignSurface
implements IDesignSurface
[code]......
Im trying to Implement the Singleton Pattern and im wondering if this is "Thread Safe" or if I am going to have to explicitly perform a SyncLock on the object instance? Example:
Public NotInheritable Class SingleTon
Private Shared _singleton As SingleTon
Private Sub New()
[Code].....
I tried it both ways, using the SyncLock and without, just not sure which one to be using?
I have an web application written in ASP.NET (FW 3.5) (along with some VBScript, this is a legacy app) that uses a utility class in the backend that logs error. I need to log several values that a user has entered in the front-end. Since the utility class has no access to the front end (or any HTTP services), i created a singleton class within the utility namespace that my front end UI can access and store information about the user.
I guess more specifically, I am wondering if there's a way to store session variables that can be shared across the web application and web services through a class referenced by both of the application and web services. For example, I have an error handling class that is used by both instances that required information about the user. Is there a way to create a per-session singleton to hold that information, so that my error class will have access to the user info?
Reading about singletons classes/pattern gave me a pretty good idea for its use. But would it be a good practice to store user related variables in properties of a thread safe singleton class so i can access them by chaining?
Example
When a user logs in several variables will be assigned to a session variable like:
Session("UserID") = reader("UserID")
Session("AccessLevels") = reader("Accesslevels")
Session("UserName") = reader("UserName")
...
Now when working on my webapplication i could always access these values by calling the session() variable, but the chance to forget the session keys or erroneous write them down is significantly. So again would it be good to store these session variables in readonly properties of singleton class so I can access them like:
MySingleton.ID
MySingleton.Accesslevels
MySingleton.UserName
So I took this from an example. GetInstance() is called from hundred different places in my program, and when I debug, the line "Prog = New Program" keeps getting hit for each of those calls. Which I thought was exactly what should NOT happen.. Or do I have some fundamental misunderstanding?
[Code]....
It seems the "New" sub triggers a number of calls to Program.GetInstance, before the first one completes. This is due to me earlier having lots of shared public objects in this class, which are no longer shared since the class was made singleton. And these objects, when initialized, calls the Program class for reference to other of it's objects.
I have a table, Users, with a related child table, UserSecurityGroups. In my GUI, the operator would select a user from a list. The program would retrieve the user record and allow the operator to edit the user data in one form. The operator could also edit the UserSecurityGroups of this user on another form.
I am considering using a singleton class for user instance retrieval and persistance back to the database. If this is a good practice, I want to use this with many other tables in my DB. My question is: Is this a good practice? What pitfalls am I missing? What would you recommend as an alternative? Would your recommendation change since I also have tables with three or four levels of relations (as opposed to two in the example above)?
Here is my proposed code:
Imports System.Data.Linq
Public Class UserConduit
Implements IDisposable
[code]....
I have an Addin for MS Excel which needs a singleton to share data amongst modules.Depending on the version of Excel (2003, 2007, 2010), and how Excel was started, it calls my addin from different, unpredictable AppDomains, which prevents the classic singleton approach.Creating a custom AppDomainManager won't work because Excel has already created the AppDomains before the addin is called.
Linking to mscoree to enumerate domains breaks the addin registration process (and I really don't want that anyway); there doesn't seem to be any other way of enumerating, so that isn't an option either.The only solution that I've found is to use remoting. Here's my test rig:
Imports System.Runtime.Remoting
Imports System.Runtime.Remoting.Channels
' Remeber to add reference to System.Runtime.Remoting DLL[code].....
Once everything is running, access to the singleton takes ~100µS, which is perfect. I can live with the ~400mS the first time each AppDomain is initialised. The problem is at startup, where the remoting invocation takes ~2.5 seconds.
Explain Singleton architecture of Remoting.
View 1 RepliesImplement singleton in a parent class.Infact what I want is that All the childs etc. should use same instance of the parent.
I have implemented singleton, Changed the scope of parent class's constructor to "Protected". But in the application when ever the new child's constructor is called i.e. "Dim abc as New Ch1()" the constructor of Parent is called (as it is Proctected and can be access from child).
I'd like to expose some functionality via a WCF service. I can configure WCF to instantiate a class per-request but am unsure how I can get a reference to a communal singleton if I were to have some functionality to store a list of calls to a method (call it LogMethod) via WCF in memory and return that list when the GetLogs method is called
I'm aware I could use a database/the file system to pass this data back an forth but in many cases, that seems to be overkill. Edit: It seems that nobody has a clear answer - I can't believe this is complex. Am I missing something obvious?
implement singleton in a parent class. Infact what I want is that All the childs etc. should use same instance of the parent.
I have implemented singleton, Changed the scope of parent class's constructor to "Protected". But in the application when ever the new child's constructor is called i.e. "Dim abc as New Ch1()" the constructor of Parent is called (as it is Proctected and can be access from child). Which is undesired behaviour.
Testing a configuration of a Windows 7 workstation acting as a "server" and a Windows XP workstation acting as a "client" (also fails in the same way using a Windows 7 client workstation).
[Code]...
I am trying to create an interface and then about 3 or 4 singleton classes that would be accessed via the interface.I know how to get interfaces to work and I know how to create concrete singleton classes and access them via GetInstance(). But when I put the two together, failure results.My problem is in the GetInstance method of the concrete singletons as in
Public Class MovingList
implements ISelectedList
[code]....
ISelectedList is the interface. This fails because ISelectedList.GetInstance is not of the type MovingList. Plus there is a problem with the use of Shared that I think is solved by simply deleting it (interfaces implicitly share).I can't define the type of ISelectedList.GetInstance because each of my singleton classes is of a different type even though they implement exactly the same properties and methods.How best to implement such singleton classes? I could do away with the interface and simply deal directly with the concrete singletons but that feels like bad practice. Programming to an abstraction not an implementation and all that.
I have a VB.NET singleton class which implements Serializable:
Imports System.IO
Imports System.Runtime.Serialization
<Serializable()> Public Class CoordinateHistory[code].....
My problem is that I can't actually call .Serialize() on the instance of this class, like all of the examples online show. What am I doing wrong?
I would like to understand the Pro & Cons in using the commonly used methods via Singleton class against Shared (Static) members of a class in VB.Net. It could be in terms Time, Space complexity or best practices. I have a BankAccount class with methods doing some business logic.
GetBalance()
GetLast5Credits()
GetMiniStatement()
[code].....
So I've been doing some research on the singleton factory design pattern, and I am wondering if my example implementation is correct (warning I did get carried away creating animals):
[Code]...
how to create password generator in vb8 small alpha and numbers to textbox anybody
View 12 RepliesIs it possible to build a Frequency Generator in VB.Net? I would like to be able to select a frequency from a Combobox or a drop down listbox. And be able to save that frequency as a file as well as play the frequency.
View 3 RepliesI have recently completed a project using VB.NET 2008 express edition. Now I have to create a Product Key Generator for which I have no clue how that works. I wanna do it in such a way that the product can't run without the valid key and the key can only be used for one copy of the product. Also if possible how do we generate a Unique Product ID?
View 3 RepliesI've been trying to work on a personal project, in which the user enters in a text string in the first text box, and when the user clicks the "encrypt" button, the SHA1 hash of the text appears in the next text box. I've googled around for some information on this, and haven't found much for Windows Forms and SHA1, only MD5. I've checked a lot of things on MSDN but to no avail.
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